The present invention relates to a cartridge for housing staples used to supply staples from a rolled sheet of staples to the sorter or finisher inside an image forming device such as a photocopier or printer.
The following is an explanation of the stapling operation of a prior art stapler with reference FIG. 1 through FIG. 5. FIG. 1 is a simplified drawing of a stapler of the prior art. The main body of the stapler consists of a frame G. A mounting unit 2 and a drive mechanism 4 are installed in the frame G.
A stapling unit 14 is attached to the mounting unit 2 with an installed cartridge 9. A stack of paper (s) is placed under the stapling unit 14 and a staple 1 is driven through the stack of paper by the stapling unit 14.
The stapling unit 14 is moved up and down by the drive mechanism 4, and drives staples through stacks of paper (s).
The following is an explanation of the staples 1 and the cartridge 9 housing the staples with reference to FIG. 2. The staples 1 used to staple documents are stored in a continuous sheet of staples (a). In other words, the staples 1 are fused together in a consecutive sheet of staples (a). The staples 1 are applied one by one to documents, where they are bent into an angular C-shape and detached from the sheet of staples (a).
The sheet of staples (a) is wound in a roll and housed inside a cartridge 9. The cartridge 9 is equipped with a housing unit 10 for housing the rolled sheet of staples (a) and a guide unit 11 for guiding the end of the rolled sheet of staples (a) from the cartridge 9. The housing unit 10 has an outer diameter that conforms to the rolled sheet of staples (a) and a round inner periphery.
The guide unit 11 for guiding the sheet of staples (a) is equipped with a pair of walls 11a, 11a held apart at a given interval, and a protrusion 11bmoving horizontally between the walls 11a, 11a. The protrusion 11b has a reverse motion stopping tab 12. The reverse motion stopping tab 12 has a tip that makes contact with the sheet of staples (a) advancing from the guide unit 11.
Guide grooves 11c, 11c are formed on the inside surface of the walls 11a, 11a. The guide grooves 11c, 11c support the sheet of staples (a). The interval between the guide grooves 11a, 11a has an angular C-shape and is roughly the length of a staple 1.
A guide tab 11c is located in the inner surface of the walls 11a, 11a, and this guide tab 11c prevents the sheet of staples (a) from rising off the base 11h of the guide unit 11.
The walls 11a, 11a are also equipped with tip contacting units 13, 13 for making contact with the main body of the device when the cartridge 9 is in the device. A catch 11g is situated on the base 11h of the guide unit 11 for keeping the cartridge 9 in a certain position inside the main body of the device.
What follows is a detailed explanation of a cartridge 9 installed in the mounting unit 2 with reference to FIG. 3. The mounting unit 2 is attached to the frame G above the base 3. The mounting unit 2 is attached to the shaft 8 on the frame G so as to be able to rotate freely.
When the cartridge 9 is installed in the mounting unit 2, the catch 11g on the cartridge 9 is drawn into the lock unit 15 formed in the mounting unit 2. The lock unit 15 is situated on the bottom of the mounting unit 2 and has a handle unit 15a, an elastic U-shaped unit 15b formed on the tip of the handle unit 15a, and a protrusion 15c protruding towards the bottom of the mounting unit 2 from the handle unit 15a. The tip U-shaped unit 15b is hung around the pin 16 on the base 3.
When the cartridge 9 is installed in a mounting unit 2 with a lock unit 15, the catch 11g on the cartridge 9 applies pressure to the protrusion 15c protruding towards the bottom of the mounting unit 2, and surmounts the protrusion 15c. Having surmounted the protrusion 15c, the cartridge 9 cannot be released because the catch 7 engages the protrusion 15c. In other words, the cartridge 9 cannot be extracted from the mounting unit 2 because of the lock unit 15.
When the cartridge 9 is removed from the mounting unit 2, the handle unit 15a is pressed down manually. When the handle unit 15a is pressed down, the end of the U-shaped unit 15b is pressed into the pin 16 and the U-shaped unit 15b is bent. The protrusion 15c is then released by the catch 11g. In other words, the handle unit 15a is pressed down and the cartridge 9 is removed from the mounting unit 2.
Also, when the cartridge 9 is installed in the mounting unit 2, the end comes into contact with the stapling unit 14. Here, the stapling unit 14 consists of a sheath bracket 17, a former 18 and a driver 19.
FIG. 4 is a detailed drawing of the stapling unit 14. A depression 18a is formed in the bottom the former 18, and a protrusion 18b is formed in the top of the former 18. This forms shoulders 18c, 18c on both ends.
The driver 19 has a bottom end that is divided into three plates with a long plate 19a in the middle and short plates 19b, 19b on the ends. A protrusion 20 is formed in the middle plate 19a, and this protrusion 20 makes contact with the former 18 on the opposite end.
The end of the middle plate 19a protrudes into the depression 18a in the former 18. The plates 19b, 19b on the ends are bent into a wedge shape, and the ends come into contact with the shoulders 18c, 18c on the former 18.
A bending block 21 is situated in the depression 18a of the former 18 and engages it. The bending block 21 has sloping sections 21b, 21b on both ends of the protrusion 21a and the protrusion 21a engages the depression 18a in the former 18.
As shown in FIG. 3, the bending block 21 is attached to the bottom of the mounting unit 2 via a spring 22, which applies spring action to the left in the drawing. Push units 18d, 18d are established in the former 18 to make contact with the sloping units 21b, 21b in the bending block 21. When the push units 18d, 18d make contact with the sloping units 21b, 21b, the spring 22 is coiled and the entire bending block 21 moves to the right in the drawing.
The top end of the driver 19 is fixed to the shaft 23, and the shaft 23 is connected so the drive mechanism 4 can move it up and down as shown in FIG. 5.
The front block 24 is attached to the shaft 23, and the front block 24 is supported by the spring shaft 25 protruding from the mounting unit 2 so that it can slide. A spring 26 is placed on the spring shaft 25 so as to apply pressure to the mounting unit 2 and the front block 24.
The mounting unit 2 is attached to the shaft 8 so it can rotate freely around the center. When the shaft 23 is raised, the front block 24 is also raised. When the shaft 23 is lowered, the mounting unit 2 is also lowered.
Therefore, when the front block 24 moves down, the mounting unit 2 moves down along the front block without compressing the spring 26 until the mounting unit 2 makes contact with the base 3. However, after the mounting unit 2 makes contact with the base 3, the spring 26 is compressed and the spring shaft 25 slides as the front block 24 moves down.
The raising and lowering of the stapling unit 14 and the mounting unit 2 by the drive mechanism 4 will now be explained in detail with reference to FIG. 5.
The drive mechanism 4 is powered by a motor 27, and the motor 27 is attached beneath the frame G. A long hole 5 is formed upward in the frame G, and a shaft 6 passes through the long hole 5. The shaft 6 passing through the long hole 5 is pressed downward by a spring 7 as shown in the drawing.
The motor 27 attached beneath the frame G has a shaft that protrudes outward from the frame G and the protruding end of the shaft has an attached pinion 28.
The pinion 28 engages a relay gear 29. The relay gear 29 is equipped with a first intermediary gear 30 having a diameter smaller than the relay gear. These two gears rotate concentrically. The relay gear 31 engages the first intermediary gear 30.
The relay gear 31 is equipped with a second intermediary gear 32 having a diameter smaller than the relay gear. These two gears also rotate concentrically. A drive gear 33 engages the second intermediate gear 32.
A pin 34 is located in the side of the drive gear 33. The pin 34 is inserted into the cam ring hole 35a in the cam ring 35. The cam ring 35 is supported by the shaft 6 attached to the frame G so as to be able to freely rotate. The shaft 6 is interposed, and an interposed support unit 35b is formed on the opposite side of the cam ring hole 35a to support the interposition of shaft 23.
The drive mechanism 4 has the same configuration on the other side of the frame G (not shown). In the drive mechanism 4, the rotation of the drive gear 33 rotates the pin 34 and shaft 6 moves the cam ring 35 up and down along the center line. In other words, the rotation of the pin 34 moves the cam ring hole 35a in the cam ring 35 upwards. The shaft 6 is interposed and the interposed support unit 35b on the opposite end is lowered. When the cam ring hole 35a is lowered, the interposed support unit 35bis raised.
A concentrically rotating cam 36 is situated on the drive gear 33, and the cam 36 presses the position detector 37a on the home position switch 37 on the frame G. When the stapling operation begins, the former 18 and driver 19 are in the initial position and the stapling operation is initiated if the cam 36 is making contact with the position detector 37a on the home position switch 37. If the cam 36 is not making contact with the position detector 37a, the motor 27 continues to rotate until contact is made. When the cam 36 makes contact with the position detector 37a, the stapling operation is initiated.
If the interposed support unit 35b is at the highest point when the cam 36 makes contact with the position detector 37a, the shaft 23 has also moved to the highest point.
The following is a detailed explanation of the feed mechanism for the sheet of staples (a) with reference to FIG. 3. The stapler performing the stapling operation described above has a feed mechanism to advance the staples. The feed mechanism is at the end of the mounting unit and consists of an advancing unit 39, a plate spring 40 and an advancing tab 42.
When a cartridge 9 is installed in the mounting unit 2, the protrusion 11b on the cartridge 9 makes contact with one end of the plate spring 40. The other end of the plate spring 40 makes contact with the advancing unit 39.
The advancing unit 39 is mounted on a shaft 41 connected to the mounting unit 2 so as to freely rotate. An advancing tab 42 is attached to the bottom. The end of the advancing tab 42 makes contact with the sheet of staples (a) drawn by the guide unit 11 from the cartridge 9, and the advancing tab 42 is positioned at a shallow angle with respect to the sheet of staples (a) moving in the forward direction.
A protrusion 39a is formed in the advancing unit 39. The protrusion 39a is positioned just beneath the driver 19 when the cartridge 9 is installed.
When the driver 19 is lowered, the protrusion 20 on the driver 19 makes contact with the protrusion 39a on the advancing unit 39. This applies pressure rightward in the drawing. Under pressure, the advancing unit 39 moves to the right while bending the plate spring 40. When the advancing unit 39 moves to the right, the advancing tab 42 also moves to the right over the sheet of staples (a). The amount of movement is equal to the width of a single staple.
When a staple 1 has been applied to a stack of paper (s) and the driver 19 is raised, the pressure on the protrusion 39a in the advancing unit 39 is released, and the plate spring 40 returns to its original shape.
When the plate spring 40 returns to its original shape, the advancing tab 42 which had moved to the right in the drawing then moves to the left. When the advancing tab 42 returns to its original position on the left, the tip of the advancing tab 42 engages a staple 1. As the advancing tab 42 moves to the left, the staple also moves to the left.
In other words, the movement from the right to the left by the advancing tab 42 extracts a single staple from the housing unit 10 in the cartridge 9. At this time, the sheet of staples (a) slides through the inner wall 10a of the housing unit 10, and the sheet of staples (a) in the housing unit 10 is fed into the guide unit 11 one staple at a time. The staple at the end of the guide unit 11 on the cartridge 9 is then moved to the stapling unit 14. The staple 1 is advanced to the stapling unit 14 as the stack of paper (s) is being stapled.
What follows is an explanation of the operation of the stapler. In a stapler with the configuration shown in FIG. 5, a stack of paper (s) is placed on the base 3, and a cartridge 9 is installed in the mounting unit 2. At this time, the bending block 21 is positioned above the stack of paper (s). A staple 1 is positioned above the stack, and the former 18 and driver 19 are positioned above the staple.
Here, the cartridge 9 is installed in the mounting unit 2 and the drive mechanism 4 is operated. When the motor 27 for the drive mechanism 4 is operated, the home position switch 37 and cam 36 are positioned above the shaft 23 in the initial position. The drive mechanism 4 is then operated to lower the shaft 23 from the initial position.
When the drive mechanism 4 is operated, the gears engage and rotate. Finally, the drive gear 33 is rotated. When the drive gear 33 rotates, the pin 34 also rotates. The rotation of the pin 34 rotates the cam ring 35 around the shaft 6 and lowers the interposed support unit 35b. When the interposed support unit 35b is lowered, the shaft 23 it supports is also lowered.
When the shaft 23 is lowered, the driver 19 it supports is lowered. When the driver 19 is lowered as shown in FIG. 4, the plates 19b, 19b on both ends press down on the shoulders 18c, 18c of the former 18, and the entire former 18 is pressed down. The long plate 19a in the driver 19 is inserted into the depression 18a of the former 18.
The lowering of the shaft 23 also lowers the front block 24. The front block 24 lowers the mounting unit 2 via the spring 7. The mounting unit 2 is lowered while maintaining a set distance from the front block 24 and not compressing the spring 7 until the bottom makes contact with the base 11.
When the cam ring 35 is rotated and the shaft 23 is lowered, the bending block 21 engages the depression 18a in the former 18.
Here, the staple 1 at the end of the sheet of staples (a) is positioned between the former 18 and the bending block 21. Therefore, when the depression 18a in the former 18 engages the bending block 21, the staple 1 is interposed between them. The staple 1 interposed between the former 18 and the bending block 21 is then bent into an angular C-shape by the depression 18a in the former 18.
When the cam ring 35 is rotated and the shaft 23 is lowered, the mounting unit 2 is also lowered and the mounting unit 2 is brought into contact with the base 3. Even when the mounting unit 2 is brought into contact with the base 3, the cam ring 35 is rotated and the shaft 23 lowered. The shaft 23 is lowered as the spring 26 is compressed by the front block 24.
When the shaft 23 is lowered as the spring 26 is compressed, the driver 19 is also lowered and the former 18 is pressed downward. When the former 18 is lowered, the push units 18d on both ends of the former 18 make contact with the sloping sections 21a on the bending block 21. When the push units 18d make contact with the sloping sections 21a, the former 18 compresses the spring 22 pressed against the bending block 21, and the bending block 21 is pushed to the right in the drawing. The pushed bending block 21 then retreats from beneath the angular C-shaped staple 1.
When the cam ring 35 is rotated, the driver 19 drives both ends of the angular C-shaped staple 1 through the stack of paper (s), and the staple 1 is detached from the sheet of staples (a).
The stack of paper (s) on the base 2 then forms a document 38, and the document 38 is stapled together by pushing the ends of the bent staple 1 through the sheets of paper. After the bent staple 1 has been pushed through the stack of paper (s), the ends of the staple 1 are folded inward. Once the staple 1 has been pushed through the stack of paper (s) and the ends have been folded inward, the stack of paper (s) is stapled.
When the cam ring 35 is rotated, the shaft 23 gradually rises. The shaft 23 rises to the top position and returns to its original position. A single rotation of the cam ring 35, in other words, brings the stapling operation to an end.
In the stapling operation, a staple is pushed through a stack of paper (s) as the feed mechanism feeds the device the next staple 1 to be applied. The next staple is positioned in the stapling unit 14 of the mounting unit 2.
The staple feed mechanism sends staples 1 one by one to the stapling unit 14. However, the feed mechanism rotates the rolled sheet of staples inside the housing unit 10 as the staples 1 are issued. As the rolled sheet of staples rotates, it expands.
Also, when a staple 1 becomes jammed, the cartridge 9 has to be removed. When the cartridge 9 is removed, the cartridge 9 is shaken. When the cartridge 9 is shaken, the rolled sheet of staples (a) moves up and down and left and right inside the cartridge 9.
When the rolled sheet of staples (a) moves inside the cartridge 9, the edge of the roll collides with the inside wall 10a of the housing unit 10 in the cartridge 9, and the impact expands the rolled sheet of staples (a).
When the rolled sheet of staples (a) expands, it expands concentrically. The rolled sheet of staples (a) expands but maintains a round shape.
When the rolled sheet of staples (a) expands, the sheet of staples (a) comes into contact with the inner wall 10a of the housing unit 10 of the cartridge 9. Because the inner wall 10a of the housing unit is round, the outer edge of the expanded rolled sheet of staples (a) comes into contact with the inner wall 10a. When the outer edge of the expanded rolled sheet of staples (a) comes into contact with the inner wall 10a, the contact area is increased. When the contact area between the sheet of staples (a) and the inner wall 10a is increased, the amount of friction between the sheet of staples (a) and the inner wall 10a also increases.
The unraveled sheet of staples (a) also exerts pressure. The sheet of staples (a), in other words, applies pressure on the inner wall 10a. The pressure on the inner wall increases the amount of friction further. When the amount of friction between the sheet of staples (a) and the inner wall 10a is increased, the sheet of staples (a) has difficulty sliding along the inner wall 10a. 
The force used by the feed mechanism to feed the sheet of staples (a) largely depends on the feeding conditions. When the amount of friction between the sheet of staples (a) and the inner wall 10a is increased, the feed mechanism may have difficulty supplying the sheet of staples (a) and a feeding error could occur.
Therefore, there remains a need for an invention that reliably feeds staples even when the sheet of staples (a) is completely unraveled.
One embodiment of the invention relates to a cartridge for housing staples having a housing unit for housing a rolled sheet of staples and a guide unit for supporting the sheet of staples drawn from the housing unit, where the cartridge for housing staples is equipped with a space forming mechanism for forming a space between the rolled sheet of staples housed in the housing unit and the interior walls of the housing unit. The rolled sheet of staples may supported along a short axis of the housing unit.
Another embodiment relates to a cartridge for housing staples, where the rolled sheet of staples forms a hollow cavity centered on the roll and the space forming mechanism has a shaft off-center from the center line of the housing unit, and the shaft supports the hollow cavity of the rolled sheet of staples. The shaft may be off-center to a degree about the distance between a bottom of the inner wall of the housing unit and the shaft. Also the shaft may be off-center beneath a center line of the housing unit.
In the cartridge for housing staples of another embodiment, the space forming mechanism is a protrusion on the interior walls of the housing unit, and the rolled sheet of staples comes into contact with the protrusion.
In the cartridge for housing staples of yet another embodiment, the space forming mechanism is an oval shaped, triangular shape or rectangular shaped inner diameter of the housing unit.